The present disclosure relates to a person support apparatus, such as a bed and with a mechanism suitable for adjusting the height and orientation of a patient support frame forming part of that bed. It is more particularly suitable for a hospital or long-term care (LTC) bed.
Person support apparatus, such as hospital and long-term care beds, typically include a patient support deck and a support surface, such as a mattress, supported by the deck. The patient support deck may be controllably articulated so as to take up different support configurations.
The patient support deck is supported on a deck support or intermediate frame and the deck support frame is provided with a mechanism for adjusting the height of the deck and hence the height of the support surface above the floor on which the apparatus is located, and to control the orientation or inclination of the deck and hence the patient support surface relative to the floor. Adjustment of the height is helpful to allow care givers to access the patient, and to facilitate patient movement into and out of the bed. The inclination of the patient support surface is also desirable so as to make the patient more comfortable, or to, for example, take up the Trendelenburg position in which the body is laid flat on the back (supine position) with the feet higher than the head by 12-30 degrees, or the reverse Trendelenburg position, where the body is tilted in the opposite direction.
The deck support frame is supported on leg assemblies which are pivotally connected at their upper end to the deck support frame and which have linear actuators for pivoting the leg assemblies relative to the deck support frame and hence adjusting the height of the deck support frame. Separate and separately controllable head end and foot end leg assemblies are provided so that the height of the foot and head ends may be separately adjusted. The leg assemblies can be pivoted together by their respective actuators and thereby raise or lower the deck support frame whilst keeping it substantially parallel to the floor. Alternatively, one of the foot or head end assemblies can be pivoted to lower just one of the foot or head ends and thereby move the deck support frame into the Trendelenburg or reverse Trendelenburg positions.
Known arrangements for pivoting leg assemblies relative to a deck support frame to allow the raising and lowering of the deck support frame include a leg element pivotally connected at its upper end to a guide element which is coupled to and can slide along the outside of longitudinal elements arranged parallel to, or forming, the sides of the deck support frame. Those known arrangements comprise a U-shaped guide element arranged on its side (i.e. with its open side extending in a vertical direction) and arranged around the outside of longitudinal elements having a rectangular cross-section. Such arrangements suffer from a number of problems. These include: i) a risk of trapping fingers in the guide element which moves along the outside of the longitudinal elements: (ii) a need to overcome the frictional forces between the inner surface of the slideable guide element and the outer surface of the longitudinal element when pivoting the leg assembly and thereby sliding; and (iii) a propensity for dust and dirt to collect on the surface of the longitudinal element and hence interfere with the sliding operation.
US 2009/0094747 and US 2010/0050343 disclose alternative arrangements in which channels which correspond to U-shapes on their sides (i.e. with an open vertical side) are arranged on the sides of the intermediate or deck support frame and have follower or guide elements extending into the interior of the channels through the vertical open side. The follower or guide elements engage and run along an interior surface of the respective channels.
US 2006/0021143 discloses a further alternative arrangement in which guide tracks or channels are defined by slots extending through the vertical sides of longitudinal bed frame elements, and the upper end of the respective leg assemblies are provided with followers extending sideways out from the upper end of the leg assemblies to extend through or into the slots. The followers run along the guide tracks defined by the slots through the vertical sides of the bed frame elements.
A need exists for further contributions in this area of technology.